The design and format of visually displayed information influences the behavior of users viewing the displayed information (e.g., how the user interprets and interacts with the information). Visual display documents, such as a web page, may undergo several design, layout, and/or format changes before and after publication. For example, web documents, such as search engine results pages (SERPs) are regularly updated in an effort to improve usability. For example, a SERP may be updated to incorporate new features and/or to improve its aesthetic appearance. When making such changes, it is often difficult to predict how user interaction with the page will be affected. For example, seemingly minor changes may have significant effects on measures of user behavior, including, for example, patterns of eye movements, clicks on objects on the web page, mouse movements, and key strokes. Such effects can be evaluated through usability studies, laboratory eye tracking studies, and live experiments on segments of traffic utilizing a modified version of the web page. Usability and laboratory eye tracking studies can be expensive and are of low statistical power. Live experiments on segments of traffic can also be expensive.